This patch adds an even more aggressive short-circuit on `!and` and
`!or` that completely avoids the evaluation of RHS operand until short
circuiting decisions are made.

Without this patch the !subst in the test drops the name "$frag" from
(one_frag:$frag ...) and returns:

```
(set FPR32_NEW:$dst, (one_frag FPR32_NEW:$a, FPR32_NEW:$b))
```

This way the dump output is roundtripable.

Rename `ListInit::getValues()` to `getElements()` to better match with
other `ListInit` members like `getElement`. Keep `getValues()` for
existing downstream code but mark it deprecated.

Initialize vectors using constructor instead of llvm::append_range when
possible.

- Add `DagInit::get` overloads that do not need ValName to be specified.
- Fix some calls to either not create temporary arrays for DAG args or
use the std::pair<> overload.

- Use range for loops in several places.
- Change some variable names to conform to LLVM coding standard.
- Use ListSeparator instead of manual code to generate comma interleaved
strings.
- Remove unnecessary copies in SETDAGOP evaluation in BinOpInit::Fold.
- Eliminate duplicated code in the 2 overloads of RecordVal::setValue.
- Use explicit type in some range for loops.
- Tested by verifying that all the .inc files generated by building all
the *CommonTableGen targets stay unchanged.

This patch partially reverts #139661 for a better solution.
Specifically, we can take advantage of the fact that std::string::find
accepts anything that can be converted to std::string_view, including
StringRef, starting with C++17.  This way, we do not need to cast Val
to StringRef or LHSs->getValue() to std::string.

Calling find/contains in the StringRef domain allows us to avoid
creating temporary instances of std::string.

Adopt `TrailingObjects` convenience API that was added in
https://github.com/llvm/llvm-project/pull/138970 in LLVM and MLIR code.